.number-line-activity{gap:var(--space-xl);min-width:0;display:grid}.number-line-activity__header{justify-items:start;gap:var(--space-sm);max-width:46rem;display:grid}.number-line-activity h1{min-width:0;font-family:var(--font-display);font-size:clamp(var(--text-lg), 3vw + .75rem, var(--text-2xl));letter-spacing:-.025em;overflow-wrap:anywhere;margin:0;font-style:normal;font-weight:700;line-height:1.12}.number-line__start-choice,.number-line__answer-choices{border:0;min-width:0;padding:0}.number-line__start-choice legend,.number-line__answer-choices legend,.number-line__jump-control p{margin:0 0 var(--space-sm);font-weight:700}.number-line__start-options{gap:var(--space-sm);flex-wrap:wrap;display:flex}.number-line__start-option{min-height:2.75rem;padding:var(--space-xs) var(--space-sm);border:var(--rule-thin) solid var(--color-rule);border-radius:var(--radius-control);background:var(--color-surface);cursor:pointer;transition:background-color var(--dur-micro) var(--ease-out), transform var(--dur-micro) var(--ease-out);align-items:center;font-weight:700;display:inline-flex;position:relative}.number-line__start-option input{opacity:0;block-size:1px;inline-size:1px;position:absolute}.number-line__start-option:has(input:checked){border-color:var(--color-group-a-deep);background:var(--color-group-a);color:var(--color-paper)}.number-line{min-width:0;min-height:9.5rem;padding-block:var(--space-xl) var(--space-lg);position:relative;overflow:visible}.number-line__track{height:var(--rule-frame);background:var(--color-frame);position:absolute;inset-block-start:5.25rem;inset-inline:0}.number-line__ticks{grid-template-columns:repeat(11,minmax(0,1fr));min-width:0;margin:0;padding:0;list-style:none;display:grid;position:relative}.number-line__tick{align-content:end;justify-items:center;gap:var(--space-xs);min-width:0;min-height:7rem;display:grid;position:relative}.number-line__tick-mark{width:var(--rule-thin);background:var(--color-frame);height:1.25rem;display:block}.number-line__tick--landmark .number-line__tick-mark{width:var(--rule-frame);height:1.75rem}.number-line__number{font-size:var(--text-md);font-variant-numeric:tabular-nums;font-weight:700}.number-line__marker{z-index:3;max-width:5.25rem;padding:var(--space-2xs) var(--space-xs);border:var(--rule-thin) solid var(--color-group-a-deep);border-radius:var(--radius-control);background:var(--color-group-a);color:var(--color-paper);font-size:var(--text-sm);text-align:center;font-weight:700;line-height:1.1;position:absolute;inset-block-start:0}.number-line__marker--current{border-color:var(--color-group-b-deep);background:var(--color-group-b);color:var(--color-ink);border-style:dashed;inset-block-start:1.85rem}.number-line__jumps{pointer-events:none;position:absolute;inset:0}.number-line__jump{width:var(--jump-width);border-block-start:var(--rule-frame) solid var(--color-group-a-deep);border-inline-end:var(--rule-frame) solid var(--color-group-a-deep);height:1.5rem;animation:number-line-jump-arrive var(--dur-short) var(--ease-out) both;border-radius:0 1.5rem 0 0;position:absolute;inset-block-start:2.8rem;inset-inline-start:var(--jump-left);transform:translate(50%)}.number-line__jump:after{border-block:.3rem solid #0000;border-inline-start:.5rem solid var(--color-group-a-deep);content:"";width:0;height:0;position:absolute;inset-block-end:-.15rem;inset-inline-end:-.35rem}.number-line__jump>span{color:var(--color-group-a-deep);font-weight:700;position:absolute;inset-block-start:-1.5rem;inset-inline:50%;transform:translate(-50%)}.number-line__jump--hint{border-color:var(--color-hint)}.number-line__jump--hint:after{border-inline-start-color:var(--color-hint)}.number-line__jump--hint>span,.number-line[data-hint-step=visible] .number-line__tick--landmark .number-line__number{color:var(--color-hint)}.number-line__jump-control,.number-line__answer-area,.number-line__hint-area{justify-items:start;gap:var(--space-sm);display:grid}.number-line__primary-action,.number-line__text-action{white-space:nowrap;cursor:pointer;width:fit-content;min-height:2.75rem}.number-line__primary-action{padding:var(--space-sm) var(--space-lg);border:var(--rule-thin) solid var(--color-ink);border-radius:var(--radius-control);background:var(--color-ink);color:var(--color-paper);transition:background-color var(--dur-micro) var(--ease-out), transform var(--dur-micro) var(--ease-out);font-weight:700}.number-line__primary-action:active,.number-line__text-action:active,.number-line__start-option:active{transform:translateY(.0625rem)}.number-line__primary-action:disabled,.number-line__text-action:disabled,.number-line__start-choice:disabled .number-line__start-option{opacity:.55;cursor:not-allowed}.number-line__primary-action[data-state=loading]{cursor:wait;opacity:.72}.number-line__primary-action[data-state=error]{outline:var(--rule-thin) dashed var(--color-error);outline-offset:.1875rem}.number-line__primary-action[data-state=success]{background:var(--color-success)}.number-line__text-action{padding:var(--space-xs) 0;border:0;border-block-end:var(--rule-thin) solid currentColor;color:var(--color-hint);background:0 0;border-radius:0;font-weight:700}.number-line__answer-grid{gap:var(--space-xs);grid-template-columns:repeat(auto-fit,minmax(2.75rem,1fr));width:min(100%,36rem);display:grid}.number-line__answer-choice{border:var(--rule-thin) solid var(--color-rule);border-radius:var(--radius-control);background:var(--color-surface);cursor:pointer;min-width:2.75rem;min-height:2.75rem;font-size:var(--text-md);font-variant-numeric:tabular-nums;transition:background-color var(--dur-micro) var(--ease-out), transform var(--dur-micro) var(--ease-out);place-items:center;font-weight:700;display:grid;position:relative}.number-line__answer-choice input{opacity:0;block-size:1px;inline-size:1px;position:absolute}.number-line__answer-choice:has(input:checked){border-color:var(--color-group-a-deep);background:var(--color-group-a);color:var(--color-paper)}.number-line__start-option:has(input:focus-visible),.number-line__answer-choice:has(input:focus-visible),.number-line__primary-action:focus-visible,.number-line__text-action:focus-visible{outline:.1875rem solid var(--color-focus);outline-offset:.1875rem}.number-line__feedback,.number-line__hint-panel{max-width:42rem;padding:var(--space-md);border:var(--rule-thin) solid var(--color-rule);border-radius:var(--radius-panel);margin:0}.number-line__feedback[data-tone=neutral]{border-style:dashed;border-color:var(--color-error);background:var(--color-error-surface);color:var(--color-error)}.number-line__feedback[data-tone=correct]{border-color:var(--color-success);background:var(--color-success-surface);color:var(--color-success);font-weight:700}.number-line__hint-panel{background:var(--color-hint-surface)}.number-line__hint-panel h2,.number-line__hint-panel p{margin:0}.number-line__hint-panel h2{font-family:var(--font-display);font-size:var(--text-base);margin-block-end:var(--space-2xs);font-style:normal}@keyframes number-line-jump-arrive{0%{opacity:0;transform:translate(50%)translateY(-.35rem)}to{opacity:1;transform:translate(50%)}}@media (hover:hover) and (pointer:fine){.number-line__start-option:hover,.number-line__answer-choice:hover{background:var(--color-surface-raised)}.number-line__primary-action:hover{transform:translateY(-.0625rem)}.number-line__text-action:hover{color:var(--color-focus)}}@media (width>=40rem){.number-line__answer-area{grid-template-columns:minmax(0,1fr) auto;align-items:end}}@media (pointer:coarse){.number-line__start-option,.number-line__answer-choice,.number-line__primary-action,.number-line__text-action{min-height:3rem}}@media (prefers-reduced-motion:reduce){.number-line *,.number-line :before,.number-line :after,.number-line__primary-action,.number-line__text-action,.number-line__start-option,.number-line__answer-choice{transition-duration:1ms!important;animation-duration:1ms!important;animation-iteration-count:1!important}}